Brewers Cup Champion Erin McCarthy On Coffee Brewing Mistakes to Avoid


[Erin McCarthy, who brews the best cup of coffee in the United States, preparing to brew. Photo: Liz Clayton]

Just exactly how hard is it to brew a really great cup of coffee? If you've gotten this far into the article, you probably already know: it can be a challenge even to the best of us—particularly if you're brewing a cup before you've, you know. Had any coffee yet.

Counter Culture Coffee's Erin McCarthy recently won the 2013 United States Brewers Cup Championship by brewing the famous Hacienda Esmeralda Geisha coffee from Panama on Kalita Wave brewers at a heated showdown in Boston, Mass. Before he heads to the world championships in Melbourne to brew the (gulp!) best cup of coffee in the world, we asked Erin what he thinks the five most common mistakes people make in their everyday brewing routines.

Mistake #1: Buying bad coffee

Not buying bad quality coffee is the first step to success, says McCarthy, who cautions that freshness—including making sure the coffee is whole bean—is key. This may be elementary to some, but when buying coffee in a grocery store (or even a specialty cafe), always check the bottom of the bag for the roast date. Many grocers have trouble with keeping the right amount of stock on hand, resulting in months-old coffee going stale on the shelves. Don't know which coffee's the best option? McCarthy has a quick tip:

"I would say that the roasters that are sourcing coffee they're really proud of, would have more information on the bag. The farmer, the processing method, etc.—anything specific on the bag beyond what the roaster's general philosophy is." Look for roasters who know and care about the chain of history of their coffee, rather than those who may be buying cheaper, lower-quality beans that could be well beyond their flavor peak.

Mistake #2: Pre-grinding

If there's anything McCarthy stresses, it's not to pre-grind coffee. Beyond how quickly the coffee begins to lose flavor after grinding (which is to say, immediately), McCarthy stresses the sensory experience of coffee brewing as a point of instruction:

"The fragrance of freshly ground coffee sets you up for what you're going to taste in the coffee, and a lot of times you get things out of the fragrance that you may not get from the extraction. That's really cool, it's getting to know another side of the coffee. Ground coffee smells really good! Why would you grind it and have that sensory experience peter out at the grocery store or the cafe where you bought it?"

For those who can't afford an expensive conical burr grinder, McCarthy suggests choosing a little elbow grease instead of a cheap blade grinder: "There are hand grinders that are burr grinders that are affordable that produce a really good grind. I don't think a blade grinder is a gateway to good grinders. It's like a choose your own adventure where you die on the third page."

Mistake #3: Using unfiltered water

Even in cities renowned for above-average tap water, McCarthy strongly recommends purified or filtered water—a filter that fits onto your faucet is just fine, he says—as an important bridge to a great cup of coffee.

"Coffee is really intensely hydroscopic," says McCarthy, "So it LOVES to pick up smells and pick up tastes. So if there's ANYTHING in your water that is maybe a little chloriney, even if you don't taste it in your water when drinking it—you'll taste it in the coffee. The cleaner your water is, the better your coffee will taste."

Mistake #4: Using water that's too cold

"I think that most people are still brewing coffee at too low a temperature," says the Brewer's Cup champ. "Whether they're using Mr. Coffees or hand-brewing, if you're pouring from a kettle that was boiled into a pouring kettle, you're losing 10 degrees. I'll either pour from my kettle that can boil, or I'll put my Takahiro [pouring kettle] back on the heat, and that helps a lot. And what that does, is these aromatics and the more delicate flavors—the fruity, the floral, and definitely the sweetness—come out more with higher temperatures. You're able to extract more out of the coffee with a higher temperature."

When brewing, McCarthy aims to have the water bed—the slurry of wet coffee grounds and water that's still extracting through it—to stay around 200 degrees F. "So that means the water when I pour it has to be 8 to 10 degrees above that," notes McCarthy.

Mistake #5: Giving up

We all horribly muck up a brew of coffee—like anything else in life—now and then. And while sometimes you only have time to put milk in it and move on, the secret to really getting better is to brew another batch. "Here's the thing," McCarthy says. "when I mess it up, if I'm trying to brew the best cup that I can, I'll do it again. And those mistakes get less and less if you're used to it," he pauses.

"If you've had enough sleep."